1. Field of the Invention
The present invention relates to a sealable cup for holding and dispensing drinkable fluids. More particularly, the present invention relates to such a cup which seals automatically when not in use, to prevent spillage of fluids therefrom. Still more particularly, the present invention relates to such a cup having simplified and sanitary valve members for regulating fluid flow.
2. Description of the Background Art
Cups are widely used for drinking liquids, usually having an open mouth. Travel mugs and some other spill-resistant cups come with lids or caps for the mouth to resist spillage of the cup contents. In addition, sports bottles are often provided with a screw-on lid having a built-in straw, and a cap for sealing the end of the straw. Some of these sports bottles also have a manually operated pop-up vent which is sealed when pushed down and open when pushed up. These sports bottles still suffer from the fact that they will empty their contents in the event the bottle is tipped sideways, unless, fortuitously, the straw had been previously manually capped, the vent had been previously manually pushed down, and the fit between the aperture in the lid and the straw was truly sealing.
One type of commercially available cup for use by anyone, and particularly well suited for small children, includes a cup body and a lid which fits sealingly on to the cup body, with a drinking spout incorporated into the lid. Some self-sealing spill-resistant cups are known and commercially available.
U.S. Pat. No. 5,079,013 to Belanger discloses a dripless liquid container for training and feeding a young person. The container of Belanger has a cup-shaped liquid housing and a lid which fits sealingly on the housing. The lid has a spout for drinking out of, with an outlet formed in the lid in fluid communication with the spout. A spring-loaded self-sealing outlet valve is provided in fluid communication with the outlet. The lid also has an air inlet formed therein which admits air to replace the volume of fluid removed from the housing, with a spring-loaded self-sealing air inlet control valve in communication with the air inlet.
U.S. Pat. No. 5,465,866 to Belcastro discloses a spill-resistant drinking cup with a built in tube for drinking therefrom. The cup of Belcastro has a cup body and a lid which is sealingly and releasably connected to the cup body The lid includes a pivotable handle, and the position of the handle determines pinching or unpinching of the tube, and, consequently, sealed and open states, respectively, of the cup. A biasing member, associated with the lid, automatically biases the handle into the sealing position when pressure is not being applied to the handle. Compressing the handle also opens an air inlet for equalizing pressure inside and outside the cup. Belcastro is also the inventor of the present invention.
A need still exists in the art for an automatically sealing cup of the Belanger type, using improved seals on the inlet and outlet thereof Preferably, the use of spring-loaded valves could be avoided for reasons of simplicity, maintenance of sanitary conditions, ease of manufacture, and cost containment.